1. Technical Field
This invention relates in general to WDM networks and, more particularly, to a method and apparatus for providing shared path protection in a WDM network.
2. Description of the Related Art
The ever-increasing needs for more communication bandwidth is driving the conversion to optical networking. The use of WDM (wavelength-division multiplexing) for the transmission of many independent communication channels on a single fiber provides a significant increase in bandwidth over single wavelength networks. Managing this huge bandwidth, however, can be challenging.
In the past, connections between nodes have been performed manually. Multi-protocol lambda switching (MPλS) now provides the structure for intelligent usage of optical resources, including capabilities for fast provisioning of wavelengths, λ-bands and even fibers.
Protection of connections remains a problem. With WDM, losing a single fiber can result in the simultaneous loss of many channels. According, a robust protection scheme is needed. On the other hand, optical resources are expensive and, therefore, must be conserved whenever possible. Ring structures, for example, provide additional protect fibers to be used in the event of a failure. The protect fibers must be located physically apart from the associated working fibers in order to prevent a single event from disrupting communications over both lines. The protect fibers, in a ring structure, are seldom used to pass traffic—a waste of a valuable resource.
Therefore, a need has arisen for a method and apparatus for efficient protection of working channels in an optical network.